The present invention relates generally to communication systems, and in particular, the present invention relates to a method for receiving short message service cell broadcast services in a GSM system.
As illustrated in FIG. 1, a wireless communication network 100 preferably includes a mobile switching center 102, a plurality of cell sites 104 each having a base station 105 coupled to a base site controller 106. Mobile communication devices 108 or portable communication devices 110 (collectively xe2x80x9cmobile stationsxe2x80x9d) are adapt to communicate with base stations associated with the base site controllers 106 to maintain communications with another mobile unit or wireline unit associated with a land line network.
The Global System for Mobile Communications (GSM) defines a teleservice that supports the concept of the transmission of a short message to all mobile stations 108, 110 within the coverage area of a base station 105. This teleservice is referred to as Short Message Service Cell Broadcast (SMSCB) service, and is identified as xe2x80x9cTeleservice 23xe2x80x9d, and permits the broadcast of unacknowledged messages to all receivers within a specific geographical region, which may comprise one or more cells sites 104, or possibly the entire Public Land Mobile Network (PLMN). Cell Broadcast messages are assigned their own geographical area of coverage by agreement between an information provider and a PLMN operator. The Cell Broadcast messages may originate from any number of Cell Broadcast Entities (CBEs) which are connected to a single Short Message Service Center (SMSC); these are the principle network elements which are involved in implementation of this teleservice. The Cell Broadcast Service (CBS) messages may comprise 82 octets each, which, using a default character set, equates to a maximum of 93 characters in length. Up to 15 of these CBS messages, (referred to as xe2x80x9cpagesxe2x80x9d in this case), may be concatenated onto one another to produce a macro-message. Each of these CBS messages comprises four 23 octet radio blocks, and four blocks are received in order during idle-mode to produce a single, CBS message, using specified addressing and link protocol specifications for the transmission of these messages.
Although this service is intended to be used to send information to users during idle mode, there is a desire for this service to be available during General Packet Radio Service (GPRS) or Enhanced Data for Global Evolution (EDGE) data transfer modes. The problem with providing such cell broadcast services during GPRS/EDGE data transfer mode is that it is not possible to receive all of the four blocks which comprise a CBS message according to current GSM specifications. Accordingly, what is needed is a method for receiving SMSCB messages during GPRS/EDGE data transfer mode without requiring a change to the current GSM specifications.